1. Field of the Invention
The present invention relates to a connector housing used for electrically connecting a wire harness of an automobile or the like, and particularly to a connector housing to which a rear holder is attached so that a connection terminal inserted into a terminal receiving chamber of the connector housing is prevented from coming off.
2. Related Art
Conventionally, there is known a connector housing having a double retaining structure which prevents a connection terminal to be inserted into the connector housing from being detached therefrom, for example, as disclosed in JP-U 64-12384.
In such a conventionally known connector housing, as shown in FIGS. 5 and 6, a female connector 31 and a male connector 32 each made of hard synthetic resin are fitted to each other. A box-like retaining member 33 with a retaining projection 34 is provided integrally on one outer circumferential surface of the female connector 31 at its front portion. A retaining plate 35 with a retaining projection 36 is provided integrally on one outer circumferential surface of the male connector 32 at its front portion. The retaining projection 34 is engaged with the retaining projection 36 so that the male connector 32 is fitted into the female connector 31.
Accompanied with this fitting, the front portions of connection terminals 43 and 44 are retained in terminal receiving chambers 37 and 38 of the male and female connectors 31 and 32 respectively, by member of retaining arms 41 and 42 respectively having retaining projections. The retaining arms 41 and 42 are provided in the terminal receiving chambers 37 and 38 so as to form primary retaining members 39 and 40 respectively.
Rear holders 49 and 50 are integrally provided on the rear end portions of the female and male connectors 31 and 32 through hinges 51 and 52 so as to form secondary retaining members 47 and 48 respectively, thereby retaining base expanded portions 43a and 44a of the connection terminals 43 and 44 provided at the base portions thereof so as not to come off connectors 31 and 32.
The configuration of the male connector 32 will be described. The female connector 31 also has a configuration similar to the male connector 32.
Retaining projections 54 are provided respectively on the opposite side surfaces of the rear holder 50 as shown in FIGS. 7 and 8 so as to be engaged with and stopped by retaining holes 56 provided respectively in the opposite side walls of the terminal receiving chamber 38. Since the rear holder 50 is designed so as to be pivotal on the hinges 52, a wire holding portion 58 of the rear holder 50 for holding a connection wire 46 at its circumference is opened in one direction to form a U-shaped configuration.
On the above configuration, first, the connection terminal 44 to which the connection wire 46 is clamped or attached by the pressure is inserted into the terminal receiving chamber 38 of the male connector 32 as shown in FIG. 6. Then, the connection terminal 44 is primarily retained in the terminal receiving chamber 38 by the retaining arm 42 with a retaining projection constituting the primary retaining member 40. When the male connector 32 is inserted to the front portion of the female connector 31, the retaining plate 35 is fitted into the retaining member 33 so that the male connector 32 is fitted into the female connector 31 and at the same time the connection terminals 43 and 44 are electrically connected to each other.
Thereafter, when the rear holder 50 is pushed into the opening portion of the terminal receiving chamber 38 while the rear holder 50 is pivoted on the hinges 52, the retaining projections 54 are engaged with the retaining holes 56 so that the rear holder 50 is fixed in the opening portion of the terminal receiving portion 38. Thus, the base expanded portion 44a of the connection terminal 44 is also engaged with the rear holder 50, so that the connection terminal 44 is doubly retained in the terminal receiving chamber 38.
However, if the wire 46 is thinner than the U-shaped width of the wire holding portion 58, the side walls of the terminal receiving chamber 38 or the U-shaped opening portion of the wire holding portion 58 of the rear holder 50 is deformed when an external force acts on the terminal receiving chamber 38 or the connection wire 46 in the transverse direction thereof as shown in FIG. 8. As a consequence, there may arise a disadvantage that the retaining projections 54 are detached from the retaining holes 56 and so the reliability of the secondary retaining member 48 is degraded.